68 BOTANICAL GAZETTE [JANUARY 
last week in June nor later than the last week in October. Its 
vegetative period, therefore, is about four months in this locality. 
Early in the summer of 1911 I started some cultures in small 
aquaria in the laboratory. These have now been under observa- 
tion for seven months and have provided a valuable check on the 
field observations. 
As shown in the accompanying figures, the mature plant occurs 
as 1-celled individuals, and as 2, 4, and 8-celled families. The 
t-celled mature individual (fig. 5) is comparatively rare; it is 
spherical in form and may or may not retain parts of the outer gela- 
tinous covering of the resting cell (figs. 1 and 3). The diameter of the 
outer wall averages 35 “and of thecell 25 #. The chromatophores 
globose, parietal, comparatively thick, and may or may not con- 
tain a pyrenoid. In young cells the chromatophore is finely granu- 
lar, in mature ones it is usually gorged with starch. The nucleus 
is centrally placed. 
The 2-celled families are abundant and exhibit a great variety 
of forms. Some of these variations are shown in the figures. The 
mother cell wall may be nearly smooth and lenticular in form, oF 
may be partially covered with a gelatinous secretion, or rarely may 
consist of two distinct layers, of which the inner one may be folded 
at the poles so that when viewed from the side it shows three ridges 
at either end (fig. 24). Except for the outermost wall, this last 
form closely resembles those from Australia. At the poles there 
are usually small ‘“‘caps” formed of a tough gelatinous secretion. 
These appear to be secreted after the loss of the gelatinous covering 
of the resting stage. STocKMAYER seems to have believed them 
to be on the inside of the mother wall, since he speaks of theif 
fusion with the “bands” in the formation of the 4-celled families. 
I have not seen any specimens, however, in which this is the case 
The “caps” are regularly external to the mother wall and the 
“bands” are regularly internal. An appearance of an external 
band is sometimes made as in fig. 6, in which an equatorial ring of 
the gelatinous secretion, which surrounded the aplanospore wall 
during the rest period, remains. 
The 2-celled families are 40—-70 m in length, 22-40 # in breadth, 
and 20-30 in thickness. The cells are spherical, or depress¢ 
